I think it's just one of those things they can't win. If they left it the same with no liberty, the game would probably only be one part, and lots of people would complain regardless, because there's a lot of stuff in FFVII that's poorly explained or completely glossed over or just archaic. I really enjoyed how they took liberties and mixed old and new and really gave a lot more background on Biggs/Wedge/Jessie, and also expanded and redid almost every aspect.
I replayed FFVII within a year of FFVII R releasing on PC @ 60 fps with mods so it was practically a 100% true remake of the original anyway, and I really enjoyed that playthrough, but I am also really glad FFVII:R is its own thing and had lots of expanded lore and surprises.
Regardless, like you said, most aspects of FFVIIR imo are miles better than this game. There's actually a whole equipment system with pro/cons and you have hundreds of combinations of materia to mix around, and there's an actual party you can control, with traditional FF elements everything, even if they did really change the type of combat, there's so many systems and layers to it all. Where this is so much more basic in almost every regard to the gameplay.
Even if you want to argue they're both pretty linear - which is true, FFXVI doesn't have anything like the "dungeons" in FFVIIR even so. Like when you're shutting down the power on top of the plate, it's a very big and actually sorta-complex area with many different platforms to move to connect you to different paths and you can actually get lost - which is something I felt missing from XVI, everything in that game is super linear, makes FFVIIR look almost open world lol.